One hundred and fifty years ago pencils first received erasers on their ends, Minnesota was admitted as the 32nd state in the Union, the Lincoln-Douglas debates were held in Illinois, and the “Wedding March,” by composer Felix Mendelssohn became popular at ceremonies marked by exchanges of the words, “I do.”

The city of Denver, too, was founded in 1858.

To mark the anniversary, the Colorado History Museum is showcasing a new exhibit, “Imagine a Great City: Denver at 150,” an ambitious effort by the museum to package the city’s history in a series of artifacts, documents, photographs, and text.

The exhibit does not take the chronological approach, the decade- by-decade march through history. Instead, Denver’s path from a tiny outpost settled by gold miners into a Rocky Mountain metropolis is covered thematically.

There is a section on transportation, with old Denver Tramway Co. benches and seats from vintage Frontier Airlines jets.

Business gets covered, with displays about guys named Gilpin and Boettcher, among others.

The conflict area contains a disturbing array of Ku Klux Klan material, including an actual white hood, a large photo of a cross burning and a contemporary KKK T-shirt. From 1922 to 1925, Colorado was second only to Indiana in KKK membership, says state historian William Convery, with 35,000 members in the state and 17,000 in Denver.

The exhibit also details Denver’s Chinatown, most of which, by the 1880s, was in an alley between Blake and Market streets, says Convery. An anti-Chinese riot on Halloween of 1880 “burned Denver’s Chinatown to the ground,” Convery says. Part of the museum’s display includes an opium pipe — Chinatown did contain a few opium dens — with a nugget of real, and vintage, opium in the chamber.

Visit the leisure area, and in addition to ski equipment, Broncos memorabilia and a beer-bottle collection, you will see a fully erected 1920s tent from Denver’s own Brooks Tent and Awning Co.

Back then, says exhibit curator Moya Hansen, people camped — for fun — in City Park and other Denver parks.

Leisure, says Hansen, is “something we rely on here in Denver.”

“We consider ourselves to be the gateway to the mountains.”

Convery said the museum staged the exhibit, which will remain in place for about two years, “to take stock.”

“Denver was one of a dozen rival camps, any one of which could have become the leading city,” he says. The city’s emergence over Golden, Auraria and other cities speaks to a variety of factors, but one of them is the people who live here and their relentless imaginations.

“It’s what has been going on from the very beginning,” says Hansen. “Imagining what this place can be.”

After fires destroyed much of the city in the early 1860s, followed by the Cherry Creek flood of 1864, there wasn’t much left of Denver.

“Why did they bother?” asks Convery. “By 1864 there were men and women who had set down stakes in Denver. They had to rebuild and persevere. They had to shout to the world that Denver was the future of Colorado.”